The aim of this project is to design a contactless speed-sensing device (tachometer) for a brushless DC (BLDC) motor. Traditional tachometers require a physical contact to the shaft of a motor to measure speed. In certain applications wherein it is not feasible to measure the speed due to safety and technical concerns, a contactless tachometer can take the readings from a certain distance.

This proposed system uses IR transmitting and receiving technique. This is achieved by receiving IR rays from a reflecting spot on the shaft of the motor. Such arrangements shall measure the rate at which the IR rays are reflecting back.

The project uses a microcontroller of the 8051 family and a pair of sensors (Transmitter and receiver) to develop a pulse for each reflection that sends an interrupt to the microcontroller.

The timer of the controller calculates the speed by each pulse received in particular time interval and displays the same. The Microcontroller is interfaced with an LCD to display the speed.

The concept of the contact-less tachometer can be enhanced and implemented in bikes, cars for speed measurement in place of a traditional analog speedometer.

Q: Can I use a large Induction motor or any other motor to sense the speed?

A: Yes, any motor with a spot reflecting surface on the shaft can be used.

Q: How can we sense the RPM reading?

A: The RPM reading can be sensed by using IR sensors interfaced to the microcontroller.

Q: What is the formula for calculating smoothing capacitor value?

A: There is some approximated formula .Peak to peak ripple voltage = Load current in amps / (2*line frequency in hertz *capacitance in farads). But as rule of thumb for 1 A current 1000uF is best. Thus it is load dependent.

I was searching Energy Meter Reading over Internet and I find in the Google.
I found my project Title so decided to buy that project
I purchase through online.

Arunima.G, ERNAKULAM on 4th November, 2015, 05:49 PM

Through my seniors i have been chosen to take the project from edgefx.
Because i had gone through our website and i found the videos ,it’s easy and understandable.
Purchased it through online.it’s Good

Amit, lonavala on 12th June, 2015, 05:12 PM

I come to know about Edgefx through friend named Harish. I directly used the Edgefx in Google.I like the everything in my kit.Yes the kit delivered on time with the right components.I purchased through online.No Suggestions.

A Ramachandran, PEROORKADA on 1st June, 2015, 11:38 AM

I came to know about Edgefx through my friend i.e., class mate he directly provided the URL i.e., www.edgefxkits.com.By seeing the output video I decided to take the kit from Edgefx and I like the Audio visuals.Yes the kit delivered on time & with right components.No I purchased the project through online. Edgefx should provide the latest new technology projects.